(function () {

    var now = {row: 1, col: 1}, last = {row: 0, col: 0};
    const towards = {up: 1, right: 2, down: 3, left: 4};
    var isAnimating = false;

    // s = window.innerHeight / 500;
    // ss = 250 * (1 - s);

    document.addEventListener('touchmove', function (event) {
        event.preventDefault();
    }, false);

    $(document).swipeUp(function () {
        if (isAnimating) return;
        last.row = now.row;
        last.col = now.col;
        if (last.row != 4) {
            now.row = last.row + 1;
            now.col = 1;
            pageMove(towards.up);
        }
    })

    $(document).swipeDown(function () {
        if (isAnimating) return;
        last.row = now.row;
        last.col = now.col;
        if (last.row != 1) {
            now.row = last.row - 1;
            now.col = 1;
            pageMove(towards.down);
        }
    })


    function pageMove(tw) {
        var lastPage = ".page-" + last.row + "-" + last.col,
            nowPage = ".page-" + now.row + "-" + now.col;

        switch (tw) {
            case towards.up:
                outClass = 'pt-page-moveToTop';
                inClass = 'pt-page-moveFromBottom';
                break;

            case towards.down:
                outClass = 'pt-page-moveToBottom';
                inClass = 'pt-page-moveFromTop';
                break;
        }
        isAnimating = true;
        $(nowPage).removeClass("hide");

        $(lastPage).addClass(outClass);
        $(nowPage).addClass(inClass);

        setTimeout(function () {
            $(lastPage).removeClass('page-current');
            $(lastPage).removeClass(outClass);
            $(lastPage).addClass("hide");
            $(lastPage).find("img").addClass("hide");

            $(nowPage).addClass('page-current');
            $(nowPage).removeClass(inClass);
            $(nowPage).find("img").removeClass("hide");

            isAnimating = false;
        }, 600);
    }
})();
